SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef3ec3253d681a9b99566dcbdf7dd25cea1d53212cd2a7728018462fb9fed7af' 
  AND token = 'kGkPC6XNwABE9QLxPAv8IpRstiqhYncHnKIzDP/LUzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}